Final answer:
Spontaneous mutations are genetic changes that occur without any external influence, typically during normal DNA replication or transcription due to natural errors. These differ from induced mutations, which are caused by environmental factors or mutagens.
Step-by-step explanation:
The mutations that arise without a known external cause are referred to as spontaneous mutations. These mutations occur during normal cellular processes, such as during DNA replication or transcription, due to mistakes made in these processes.
Unlike induced mutations, which result from exposure to environmental factors or mutagens like radiation, chemicals, and infectious agents, spontaneous mutations happen naturally and are not caused by an external factor. Mutagenesis can occur either spontaneously or be induced, with spontaneous mutagenesis happening as a natural part of cellular reactions and induced mutagenesis resulting from environmental exposure.
It is crucial to understand that both spontaneous and induced mutations contribute to the genetic variations observed within populations, but they happen due to different mechanisms. Spontaneous mutations play a significant role naturally, whereas induced mutations are a result of environmental influences.